1. Field of the Invention
The present invention relates to a steering wheel with an air bag device, and more particularly to a steering wheel in which an airbag device can be attached thereto and detached therefrom in a simple fashion.
The present application is based on Japanese Patent Application No. 2000-26832, which is incorporated herein by reference.
2. Description of the Related Art
In a conventional steering wheel with an airbag device, as disclosed in SP-A-11-11247, an airbag device is attached to a core plate on a steering wheel main body at left and right sides thereof with bolts.
As described above, however, in attaching the airbag device to the steering wheel main body by rotationally tightening the bolts, the tightening torque needs to be controlled, and since a plurality of bolts are used, labor hours are needed not only for attachment but also for detachment of the airbag device.
Furthermore, an operation hole needs to be provided in the steering wheel main body for inserting a tool such as a screw driver for use in tightening or loosening the bolts, and conventionally such operation holes are opened in lateral sides of a lower cover disposed at a lower portion of the steering wheel main body, this deteriorating the external appearance of the lower cover.
The invention was made with a view to solving the above problems, and an object thereof is to provide a steering wheel with an air bag device in which the deterioration in external appearance thereof can be suppressed and in which an air bag device can be attached thereto and detached therefrom in a simple fashion.
According to the invention, there is provided a steering wheel with an airbag device in which the airbag device is mounted on a steering wheel main body at a plurality of connecting points, the steering wheel with an airbag device being characterized in that connecting pins are provided on one of the steering wheel main body and the airbag device at the respective connecting points in such a manner as to protrude toward the other, and connecting levers are disposed on the other of the steering wheel main body and the airbag device in such a manner as to rotate in a direction substantially normal to an axial direction of the connecting pin, that the connecting pins are each constituted by a locking portion disposed at a distal end of the pin and having a tapered and inclined guide surface and a small diameter portion disposed at a proximal end thereof and having a diameter which is smaller than that of a proximal end of said locking portion, that the connecting pins each comprise a hook portion adapted to be inserted in the small diameter portion of the locking pin for locking a proximal portion of the locking portion and an operating portion for operating the hook portion so as to rotate in a lock releasing direction and is biased in a locking direction, and that the hook portion interferes, when connected, with the guide surface of the connecting pin which is being forced in the axial direction of the connecting pin so as to be located at a waiting position where the hook portion is allowed to rotate in the lock releasing direction.
Then, it is desirable to create a large diameter portion, having an larger outside diameter than the outside diameter of said locking portion, at the distal end of the connecting pins. Further it is desirable that fitting holes for allowing the large diameter portions to fit therein when the distal portions of the locking portions are locked by the hook portions are disposed in the other side of the steering wheel main body and the airbag device where the connecting levers are disposed.
In addition, it is desirable to dispose springs on the side of the steering wheel main body and the airbag device where the connecting pins are disposed. These springs are adapted to be brought into abutment with the other of the steering main body and the airbag device where the connecting levers are disposed and to bias the connecting pins respectively along the axial direction of the connecting pins and in a direction in which the connecting pins move away from the hook portions.
In the steering wheel according to the invention, when the airbag device is mounted on the steering wheel main body, the connecting pins are forced into the side where the connecting levers are disposed.
Then, the hook portions of the connecting levers interfere with the guide surfaces of the connecting pins which are forced in along the axial direction thereof to thereby be located at the waiting positions where the hook portions can rotate in the lock releasing direction, whereby as the connecting pins are forced in, the hook portions rotate in the lock releasing direction while being guided along the guide surfaces. Then, when the small diameter portions come to be disposed at the positions of the hook portions, the hook portions are inserted into the small diameter portions by the biasing means to thereby lock the distal portions of the locking portions such that the connecting pins cannot be dislocated. As a result, the air bag device comes to be mounted on the steering wheel main body.
Namely, when mounting the air bag device on the steering wheel main body, the connecting pins only have to be forced into the side where the connecting levers are disposed, as a result of which the air bag device is mounted on the steering main body in a simple fashion.
Thereafter, when dismounting the air bag device from the steering wheel main body, a tool such as a pin is hooked on the operating portion of the connecting lever so as to rotate the connecting lever in the lock releasing direction in which the hook portion is released from the locking state, then the air bag device is moved such that the connecting pins are pulled out of the hook portions. As a result the air bag device can be dismounted from the steering wheel main body.
Additionally, the tool used to rotate the connecting lever may be such that it simply hooks on to the operating portion of the connecting lever so as to slightly rotate the connecting lever, and such an operation can be effected from the bottom face side of a lower cover and the like of the steering wheel main body. Therefore, even if operational holes are to be provided, the operation holes can be opened not in the top or the side face but in the bottom face of the steering wheel main body. Consequently, the external appearance of the steering wheel is not deteriorated. Of course, even if the operation holes are opened in a side face of the steering wheel main body, these operating holes are smaller in diameter than the operation holes for the tool such as a screw driver may be opened, since the tool for rotating the connecting lever is such that the tool simply hooks on to the operating portion so as to slightly rotate the connecting lever, namely the tool may comprise a pin of a thin wire material or the like. As a result, the deterioration in external appearance of the steering wheel can be suppressed to an extreme extent.
Accordingly, with the steering wheel according to the invention, while suppressing the deterioration in external appearance of the steering wheel, the air bag device can simply be mounted on and dismounted from the steering wheel main body.
Then, the large diameter portion having the larger diameter than the locking portion is provided at the distal portion of the connecting pin, and the fitting holes are formed in the side where the connecting levers are disposed in order to allow the large diameter portions to be inserted thereinto when the distal portions of the locking portions are locked by the hook portions. According to this construction, when the air bag device is mounted on the steering wheel main body (when the distal portions of the locking portions of the connecting pins are locked by the hook portions of the connecting levers), the large diameter portions of the connecting pins are allowed to fit in the fitting holes, whereby the movements of the connecting pins in directions normal to the axes thereof are restricted, to thereby make it possible to prevent the loosening of the connecting pins in the directions normal to the axes thereof in the air bag device.
Additionally, the disposition of the springs on the side where the connecting pins are disposed, such that these springs are adapted to be brought into abutment with the side where the connecting levers are disposed and to bias the connecting pins respectively along the axial direction of the connecting pins and in the direction in which the connecting pins move away from the hook portions, can provide the following operations and advantages.
Namely, when the air bag device is mounted on the steering wheel main body (when the distal portions of the locking portions of the connecting pins are locked by the hook portions of the connecting levers), the connecting pins are biased respectively along the axial direction thereof and in the direction in which the connecting pins move away from the hook portions by the biasing force of the springs so that the hook portions of the connecting levers are brought into abutment more securely with the distal portions of the locking portions of the connecting pins. Therefore, the distal portions of the locking portions are locked by the hook portions, so that the movement of the connecting pins in the direction in which they move away from the hook portion is restricted. On the contrary, the movement of the connecting pins in a direction in which the connecting pins are forced into the hook portions is restricted by the biasing force of the springs. As a result, when the air bag device is mounted on the steering wheel main body (when the distal portions of the locking portions of the connecting pins are locked by the hook portions of the connecting levers), the movement of the connecting pins in the axial direction thereof is restricted, to thereby make it possible to prevent the loosening of the connecting pins in the axial direction thereof in the air bag device.
Additionally, when the air bag device is mounted on the steering wheel main body (when the distal portions of the looking portions of the connecting pins are locked by the hook portions of the connecting levers), since the connecting pins are biased respectively along the axial direction thereof and in the direction in which the connecting pins move away from the hook portions by the biasing force of the springs, in the event that the tool hooks on to the operating portion so as to rotate the connecting lever to thereby release the hook portion from the locking state, the connecting pin is easily released from the hook portion by the biasing force of the spring, and thereafter, even if the tool is removed from the operating portion so that the connecting lever is biased to be restored to its original position, the locking portion of the connecting pin keeps released from the hook portion, consequently, the air bag device can be easily dismounted from the steering wheel main body without the interference of the connecting pins with the connecting levers.